PRODUCT CATALOGUE - Specac

Specac Product Catalogue 2011 | Spectroscopist’s Hints and TipsSpectroscopist’s Hints and TipsThe following hints and tips on Infrared Sampling may help you achieve better spectra withgreater ease. Don’t forget to contact your local Specac representative if you need any helpwith your application. Contact details are listed at the back of this catalogue.Reflection MeasurementsTwo ways of reducing the ATR penetration depthinto a strongly absorbing sample are choosing anATR crystal with a higher refractive index (see thelist of optical material properties at the back ofthis catalogue), and selecting a larger angle ofincidence.When analyzing powdered samples using ATR,pre-grinding the sample will improve thehomogeneity of the sample particles, and yieldbetter spectra.Aerosol spray samples can be convenientlyanalyzed using the ATR technique. Spray thecontents onto a flat or trough top-plate, in a fumecupboard, away from the spectrometercompartment.Lacquers and coatings can be analyzed forspecular reflectance in the following way. Wrapaluminium foil (shiny side out) around thereference mirror and apply the coating. Allow todry and record spectra of the resulting film.When using diffuse reflectance the sampleheights are not alway uniform. Each time thesample is changed it is desirable to reach theoptimum height and peak energy as quickly aspossible. A rolling micrometer on the SpecacMinidiff Plus accessory adjusts the height inseconds, without using tools.Level the surface of a sample for diffusereflectance measurement by gently tampingdown the surface, using a glass slide resting onthe surface under its own weight. Do not pressthe surface hard, and risk compacting thesample. The surface can be seen through theglass slide.www.specac.com103